I just installed rsync version 2.6.3 using CYGWIN under Windows XP on my DELL laptop. I attempted the following command: rsync -avuzp -e ssh machine-name:~/work work machine-name is my work machine running linux. The error I get is: lseek failed in map_ptr rsync error: error in file IO (code 11) at fileio.c(228) rsync error: received SIGUSER! or SIGINT (code 20) at main.c(880) This exact command works fine when use it to synchronize my home PC with my work machine. On my home PC, I run linux and have rsync version 2.6.2 installed. So then I installed rsync version 2.6.2 on my laptop and got the exact same error as above.
I've never been able to reproduce this bug. Are you using the official 2.6.3 cygwin version, or one you compiled yourself? I've checked in an improved error message for when the lseek fails, so if you're still seeing this bug, give 2.6.4pre2 a try (coming soon) and see if it will give us a better idea of what is going wrong.
No word that this is still a problem, so closing.